Method and apparatus for filtering liquid in a clothes washing machine



Aug. 9, 1966 A. MASON 3,264,661

METHOD AND APPARATUS FOR FILTERING LIQUID IN A CLOTHES WASHING MACHINEFiled May 1, 1964 5 Sheets-Sheet x INVENTOR. A12 bany [Jason A TTO E YSAug. 9, 1966 A. MASON 3,264,661

METHOD AND APPARATUS FOR FILTERING LIQUID IN A CLOTHES WASHING MACHINEFiled May 1, 1964 :5 Sheets-Sheet 2 INVENTOR. Hzzfiozg Mason a e fT6RN%s A g. 1966 A. MASON 3,264,661

METHOD AND APPARATUS FOR FILTERING LIQUID IN A CLOTHES WASHING MACHINEFiled May 1, 1964 5 Sheets-Sheet 3 INVENTOR. Aazaay %6*O12 A TTORNEYSUnited States Patent METHOD AND APPARATUS FOR FILTERING LIQUID IN ACLOTHES WASHING MACHINE Anthony Mason, Benton Harbor, Mich, assignor toWhirlpool Corporation, Benton Harbor, Mich, a corporation of DelawareFiled May 1, 1964, Ser. No. 364,090 12 Claims. (Cl. 8158) The presentinvention relates to home appliances and more particularly concernsimprovements in filtering apparatus for laundry machines.

In the course of a washing cycle in a washing machine, washing orrinsing fluid drawn from the bottom of the tub or pool may be returnedthereinto. In order to avoid return of lint and other entrained foreignmaterial with the recycled water, it is desirable to have a filtersomewhere ahead of discharge of the returned water into the pool or tub.From time-to-time the filtering device must be cleaned to remove thelint and foreign material filtered out of the water.

An important object of the present invention is to provide a new andimproved filter structure for laundry machines which is of simple andinexpensive construction comprising a small number of rugged, longlasting parts,=

and which may be installed and removed for cleaning conveniently andeasily.

Another object of the invention is to provide a new and improved filterapparatus which is especially suitable for domestic Washing machines ofthe wringer type.

A further object of the invention is to provide a novel filteringapparatus which can be installed directly in the washing pool or tub ofa domestic washing machine of the agitator type.

Still another object of the invention is to provide a new and improvedfiltering unit which is of unusually large capacity in a small unit.

Other objects, features and advantages of the present invention will bereadily apparent from the following detailed description of a preferredembodiment thereof taken in conjunction with the accompanying drawings,in which:

FIGURE 1 is a fragmentary plan view, partially in section, disclosingfeatures of the invention;

FIGURE 2 is a vertical sectional elevational view taken substantially onthe irregular section line IIII of FIGURE 1;

FIGURE 3 is a front elevational view of the filter device alone;

FIGURE 4 is a vertical sectional elevational view taken substantially onthe line IVIV of FIGURE 3; and

FIGURE 5 is a horizontal sectional detail view taken substantially onthe line V-V of FIGURE 3.

While the principles of the present invention as embodied in a filterunit 7 may be useful in other environments, an especially usefulapplication of such principles is demonstrated in a domestic laundryappliance such as a clothes washing machine 8 of the well-knownoscillatory agitator type and including a stationary tub 9 of suitablesize within which a load of clothes, wash water and detergent areagitated during a washing period. For efficiency and economy,recirculation of the washing water for different and successive loads ofwash is desirably effected through a recirculation conduit 10 by meansof the usual pump (not shown). Suitably the recirculation conduit 10 maybe mounted by means of a bracket structure 11 on and alongside the usualwringer drive shroud 12. Entry of the recirculation conduit 10 into thetub 9 is effected by means of an upper gooseneck or inverted U-shapedportion 13 extending through a suitable opening 14 provided for thispurpose in the "ice upper part of the tub well above the water line andhaving its edge protectively encased in a suitable rubber grommet 15.Access into the tub 9 from the top is through the usual top openingdesirably closed by a removable cover 17.

According to the present invention, the filter unit 7 is constructed andarranged to be removably mounted within the tub 9 at a suitable locationto be detachably connected to the recirculation water conduit gooseneck13 and to be substantially submerged in the wash water. To this end, thefilter unit includes as the major component a generally flattened,upwardly opening pocketlike receptacle 18 having a front Wall 19 and arear wall 20 which are desirably generally parallel vertically but areof oppositey bowed arcuate shape horizontally and merge at their sideswhereby to afford a generally lanceolate cross-section. A bottom wall 21joins the lower ends of the walls 19 and 20 and provides therewith areceptacle of substantial volume elongated horizontally and opening atthe top. Reinforcement for the upper end of the front wall 19 isafforded by a forwardly directed integral flange 22 which also serves asa convenient handle for manipulating the filter unit receptacle.

For removably mounting the receptacle 18, the bu'ging arch of the rearwall 20 is preferably formed complementary to the arc of the insidediameter of the vertical wall of the tub 9, and means are provided onthe rear wall for supported interengagement thereof with a mountingblock bracket 23 carried by the tub wall. This bracket 23 may be formedas a die casting or molded rigid plastic member and carries or isengageable with the head of a securing screw 24 the shank of whichextends rearwardly through a complementary hole 25 in the tub wall andis secured as by means of a nut 27 by which the head of the screw istightly drawn up to secure the filter-supporting bracket 23 firmly inplace.

To facilitate quick and easy mounting and removal of the filterreceptacle 18 with respect to the supporting bracket 23, and to assurepositive retention of the receptacle and firm engagement of the backwall 20 thereof against the tub wall, the bracket 23 is constructed ofgenerally truncated wedge-shape, with its narrow end extending upwardly,and the back wall 2t) is provided with a complementary rearwardlyopening bracket socket 28 as best seen in FIGURES 2, 3 and 5. A dovetailformation of the upwardly tapering sides of the bracket 23 andcomplementary undercut groove formation of the opposite side walls 29defining the socket 28 effects a satisfactory interengagement of thereceptacle with the retaining bracket. To bias the receptacle toward theWall of the tub 9, the bracket 23 is constructed thickest at its upperend and with its front wall tapering rearwardly from the top down, andthe walls defining the socket 28 are of complementary shape. Throughthis arrangement, mounting of the filter receptacle 18 is readilyeffected by moving it downwardly to engage the supporting bracket 23 inthe socket 28.

In order to hold the receptacle 18 in its mounted position againstupward displacement by the force of water and wash load as driven by theagitator of the machine, a suitable quick releasable latch 36 isprovided. A desirable form of this latch comprises an upwardlyprojecting resiliently flexible latch lever 31 having on its lower end aforwardly opening generally U-shaped engagement base 32 engaging arearwardly extending attachment flange 33 on the upper end of thebracket 23. Overlying the latch supporting flange 33 in spaced relationin the assembly is a keeper flange 34 which closes the top of the socket28 in the rear wall 20 of the receptacle and serves as reinforcement. Aclearance opening 35 in the front portion of the reinforcing and keeperflange 34 and the adjacent juncture of the front wall defining thepocket 28 clears the latch lever 31 therethrough and enables a latch dog37 to engage upon the keeper flange 34 and thus retain the receptacle 18against unintentional upward displacement.

Suitably, the latch arm 31 may be made from noncorroding metal, but inthe form shown comprisesqa semi-rigid resilient plastic material ofwhich polypropylene is quite satisfactory. Above the latch dog 37 anupwardly and forwardly inclined latch handle extension flange'38 on thelatch lever provides a lead-in cam head engageable with a cam edge 39defining the rear of the latch opening 35 during assembly of thereceptacle 18 with the supporting bracket 23. Thus, during the assemblymovement of the receptacle'into position, the cam head.

flange 38 is engaged by the cam edge 39andthe latch lever 31 flexedforwardly to clear the latch dog 37 past the edge 39, until fulldownward assembly of the receptacle 18 on the bracket 23 has beeneffected whereupon the latch dog 37 snaps into latching engagementoverthe keeper flange 34. To release the receptacle 18, forwardly directedmanual pressure against the lever arm handle within the receptaclethrough a large area discharge open-- ing 40 in the front wall 19. Afilter screen 41 extends entirely across the discharge opening and in adesirable form comprises a 36-mesh stainless steel screen wire suitablefor domestic washing machine use. Where, 'as in the illustratedinstance, the receptacle 18 is made of a suitable plastic material suchas polypropylene, the screen 41 may bemounted with its margins directlyembedded and locked in the material of the front wall 19 about frontwall 19 to assist in stiffening the front wall against" collapsingrearwardly under the agitated load within the tub 9 in service. As bestobserved in FIGURES 2 and 3, the opening is elongated horizontally andhas its the filter receptacle 18 in relation to predetermined waterlevel W in the tub 9 is with the upper side of the discharge opening 40adjacent to and desirably below the Thereby, slinging turbulence. forceof the water level. agitator motivated water ,in the tub 9 providesabackflushing action on the screen 41, as indicated by direc-, tionalarrows, to dislodge lint or other foreign material from the screen fordeposit in the sump area of the'recepwash 'to escape into the receptacle18 or to get hung up thereon is avoided by the overhanging reinforcingand handle flange 22 which thus serves as a deflector lip."

During feeding of recirculation water into the receptacle 18 from theconduit 10, flow-blocking collection.

of lint and foreign matter on the inner side of the filter screen 41 issubstantially prevented by maintaining a flushing circulation of thefed-in water across the screen.

'tacle Further, any tendency. for turbulently. moving To this'end, thewater from the conduit 10 is fed through i the gooseneck 13 into avertical manifold 43 within one side of the receptacle chamber spacedefined by a vertical.

partition and the adjacent converging portions of the front and rearwalls 19 and 20.: At its lower end, the manifold is closed by the bottomWall 21. At its upper end, the manifold 43 is closed by a top closureflange 45 (FIGS. 1 and 4) having an upstanding nipple 47 of 4 an outsidediameter to receive the discharge endof the gooseneck 13 thereabout;with an O-ring seal providing a water seal for the relatively low waterpressure delivered by therecirculation water conduit. From the manifold43 water under the relatively low but nevertheless subs stantialrecirculation pump pressure dischargeinto'the main'portion of the filterreceptacle chamber through a vertically elongated but limited lengthdelivery orifice 49 (FIGURES3, 4 and 5) provided between the front;

wall 19. and the adjacent edge of the manifold partition 44. By havingthe delivery orifice .49=aligned with the adjacent side of the deliveryopening 40 :and preferably adjacent the upper-portion of such side,water discharging from the manifold 43 takes the: formof a flaringstream whichcontinuously flushes the ,inner face of the subs mergedfilter screen 41 and thus:tends to avoidthe clogging of the screen 41 bylint: and other foreign matter carried over in the recirculation water.The general flow pattern of the water. thus delivered is, indicated bydirectional arrows in FIGURES. 3 and 5. As the force of the streamdiminishes, especially inthe side area-.of the. receptacle chamberopposite from the manifold 43, the

lint and foreign matter tends to settle out into the sump area in thebottom of the receptacle :chamber formed by walls 18a and 18b. Thus, thesubmerged screen 41. is not only flushed continuouslyfreefrom lint andother.

foreign matter by the transversely directed stream from the deliveryorifice: 49 :during feeding in ofthe recirculationwater, but duringoperation of the washing machine backflushing of the screen, asalreadydescribed, assures dislodgmentfrom the inner aceof thetscreen of'anylint or foreign ,matterthat may. collect thereon despite the transverseflushing delivery stream or which may collect thereon after the deliverypressure has been discontinued and ordinary drainage through the.discharge opening 40;

occurs. It may beobserved in FIGURES 2 .and 3, that the downwardly andrearwardly sloping wall defining the hanger bracketreceiving socket 28provides a downward deflecting surface facilitating diversion-ofbackflu'shed lint and the like downwardly toward the sump area in thefilter receptacle chamber.

In order to facilitate molding of-the receptaclelS from a suitableplastic material such as polypropylene to provide a semi-rigid,resilient receptacle frame, and to facilitate cleaning of the receptacle18, the frontand rear portions of the; receptacle are preferablyvseparably constructed asrespective shells 18aand18b Whilethese shellsmay be completely separable, a preferred construction comprises. hingingthe same such as by the provision of an integrally molded hinge, 50along the base portion of aparting 51. At" the opposite: sides thesections 18a and 18b have respectively thickenedreinforcing framemargins 52.and 53substantiallyabutting at the-parting 51 (FIGURES'L' 3and 5).

To serve as part of a pressure-responsive latch means to hold the shellsections 18a and 18b together separably, the manifold partition 44'isiformed integrally with the rear section 18b and with its verticaledge adjacent to .but spaced fromthe frontwall 19. Vertically aligned,spaced grooved upper and lower gripping jaws 54 and 55 define betweentheir ends andwith thecontiguous edge of the partition 44 a gap whichaffords the delivery orifice 49.-

Eachof the gripping jaws Stand 55 comprises a pair of opposed, stifllyresilient, vbulbous.cross-section gripping elements which are normallyspaced apart slightly, less than the thickness of the, contiguous marginof the parti tion 44 so as to frictionally grip .such'margin firmly, butreleasably, when pressed intoengagement betweenthe jaws. Through thisarrangement, it is easy to openthe receptacle ;18,by pulling the jaws.54 and 55' free from r the engaged margin ofthe partition 44 whileswinging the sections 18:: and 18b aboutthe hinge, .50. Closing of thesections 18a and 18b. is easily effected by pressing them toward ,oneanother until the end margins 52 and 53 abut and the gripping jaws 54and 55 .retainingly grasp the partition margin throughout theirsubstantial lengths. By having the jaws 54 and 55 in engagement with thepartition 44, any tendency toward separation of the receptacle sections18a and 1812 under the head of the water column in the manifold 43 iseffectively resisted. Since recirculation water escapes with substantialfreedom from within the receptacle 18 through the discharge opening 40,and when the tub 9 is filled the receptacle is substantially submerged,and pressures against the receptacle, if any, are toward the outside ofthe section 18a, tending to press it toward the section 18b which is inturn anchored on the bracket 23 and against the wall of the tub 9,assurance is had against unintentional open ing of the receptacle alongthe parting 51.

To further provide a latching means to hold shell sections 18a and 18btogether, end margins 52 is provided with hooked projections 52a thatmate with recesses 53a in end margins 53, such as shown in FIGURE 5. Themating of hooked projections 52a with recesses 53a provides asemi-positive latching means for the frame margin. The frame margin canbe readily separated by the operator by manually applying force thatwould cause the resilient hooked projections to yield from the latchedposition.

Strengthening of the partition 44 is effected by integral attachment toits upper end of the upper closure and nipple flange 45 which isconveniently constructed as an integral part of the rear wall 20 and theadjacent thickened side frame margin 53. Additional reinforcement andclosure for the upper end of the manifold 43 is provided by acomplementary flange portion 58 on the upper end of the front wall 19overlappingly related to the adjacent portion of the nipple flange 45and complementally engaging in the closed assembly of the sections 18aand 18b about the base of the nipple 47.

From the foregoing it will be apparent that the present invention hasprovided a substantially new and improved filter device especiallysuitable for use with domestic washing machines for filteringrecirculation water. Such filtering device is constructed and arrangedin convenient position within the washing machine tub, is readilyremovable for cleaning, is easily and quickly opened to be cleaned outand is easily and conveniently reassembled and remounted for service. Inaddition to other numerous features of novelty, the novel delivery ofrecirculation water with respect to the filter screen to provide aflushing stream thereacross affords substantial advantages. In addition,the submerged disposition of the screen permitting back-flushing of thesame by force of agitator impelled wash water further increases thecapacity of the filter receptacle without clogging of the screen. Sincethe filter screen is maintained free of clogging lint or other foreignmaterial, internal pressure build-up within the filter receptacle isavoided, and simple squeeze pressure friction retaining means sufficesto hold the separable, hinged sections of the receptacle together untildeliberately pulled apart for cleaning of the receptacle.

Although minor modifications might be suggested by those versed in theart, it should be understood that I wish to embody within the scope ofthe patent warranted hereon all such modifications as reasonably andproperly come within the scope of my contribution to the art.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A method of filtering liquid containing foreign matter liable to cloga filtration screen,

delivering liquid containing the foreign matter into a receptacle havingan opening through an upright wall and across which opening a filteringscreen extends,

and while continuing to deliver recirculation liquid into the receptacledirecting a flushing stream of liquid generally horizontally across theinner face of the screen from one side of the opening and into a chamberarea of the receptacle beyond the opposite side of the opening, wherebyas the flushing stream diminishes in velocity into said chamber spaceforeign material flushed from the screen tends to sink to the bottom ofthe receptacle.

2. Filtering apparatus adapted for use in a laundry machine having a tubfor containing a laundry liquid and further including an agitatormechanism, comprising:

a filtering device comprising a receptacle including a back wall and afront wall,

said back wall having means for attaching the same in filteringposition,

said front wall having a screened discharge opening,

said discharge opening being submerged in said liquid,

means defining a delivery manifold on said receptacle communicating withthe interior of the receptacle,

and means for communication of a liquid delivering conduit with themanifold,

said manifold being located adjacent to one side of said opening andhaving a delivery orifice directed to drive a flushing stream of liquidfrom the manifold transversely across the inner surface of the screen.

3. A filtering device adapted for use in a laundry machine having a tubwith a circular upright wall for containing a laundry liquid,comprising:

an upwardly opening receptacle of generally lanceolate horizontalcross-section providing a front section and a back section joined by awall at the bottom affording a sump area within the receptacle,

said back section being of a curvature substantially complementary tothe curvature of the tub wall, means for removably attaching said backsection conti guous the tub wall,

means for delivering liquid to be filtered into the receptacle,

said front section having a discharge opening,

said discharge opening submerged in said liquid,

a filtering screen across said discharge opening,

and the lower edge of the discharge opening being substantially abovesaid bottom wall.

4. A filtering device adapted for use in a laundry machine having a tubwith a circular upright wall for containing a laundry liquid,comprising:

an upwardly opening receptacle having a front section and a back sectionjoined by a wall at the bottom affording a sump area within thereceptacle,

said back section, being of a curvature substantially complementary tothe curvature of the tub wall, means for removably attaching said backsection contiguous the tub wall,

means for delivering liquid to be filtered into the receptacle, saidfront section having a discharge opening,

a filtering screen across said discharge opening,

the lower edge of the discharge opening being substantially above saidbottom wall,

said sections being separate along a parting extending through theirmeeting margins and along said bottom wall,

a hinge securing the bottom wall portions at each side of the parting,

and means for separably retaining the sections together and enablingopening of the sections for cleaning out the sump area.

5. A filtering device as defined in claim 4, wherein said separableretaining means comprise frictional gripping means on one of saidsections releasably engaging other of said sections.

6. A filtering device adapted to filter recirculation water in a laundrymachine comprising a tub having a pool of turbulently agitated washwater and wash therein,

said device including a receptacle having means for mounting it inpartially submerged relation within the pool in the tub,

means for receiving recirculation water into the receptacle, the upperend of the receptacle being open and located above the pool of water andthe lower end of the receptacle defining a foreign matter receivingsump.

therein, a front wall on the receptacle having a discharge openingtherefrom, a filtering screen across said opening, and flange meansprojecting from the upper end portion of the front wall and sewingto'defiect wash turbulently motivatedtoward the'top of the receptacle toprevent catching of the wash on the top of the receptacle or enteringinto the top opening into the receptacle. 7. In a filtering deviceadapted for use in a laundry machine having a tub,

a receptacle having liquid receiving means and a filtering opening, asupporting bracket of truncated wedge-shape provided with dovetailupwardly converging sides, said receptacle having a wall providedwith asocket receptive of said bracket, and means along opposite sides of thesocket defining undercut grooves complementary to and retaininglyengageable with said dovetail sides of the bracket. 8. A filteringdevice adapted for use in a laundry machine having a tub,

said device including a receptacle, a bracket for attachment to the tuband removably engageable by the receptacle, and releasable latch meanscarried by the bracket and engageable with keeper means on thereceptacleito retain the receptacle against unintentional displacementfrom the bracket 9. A filtering device for filtering laundry liquidcomprising,-

a receptacle having an upright wall formed with. an

opening in said wall, a filtering screen extending across said opening,means for receiving laundry liquid in said receptacle including meansfor directing a flushing stream of said laundry liquid generallyhorizontally'across the inner face of the filtering screen from oneside" of the opening and into a chamber area ofthe receptacle beyond theopposite side of said opening, whereby as the flushing stream diminishesin velocity into said chamber space foreign material flushed from thescreen tends to sink to the bottom of the receptacle.-

machine having .a tub, for containing a laundry liquidrecirculation'means including a conduit foridelivering recirculated laundry liquidinto an upper portion 1 horizontally across the inner face .of thefiltering screen from one ide of the opening and into a chamber areaofthe receptacle beyond-the opposite side of said opening,

and a sump area in [the bottom of the receptacle receiving the foreignmaterial which is flushed fromthe screen and which settles whenthe'fiushing stream diminishes in velocity.

11.;The invention of claim 10 and further charac terized by agitatormechanism in the tubfor agitating the contents of the tub and foradditionally assisting the flushing of the screen by a back-fiow-actionthroughthe screen.-

'12.iFiltering apparatus adapted for use in a laundry and furtherincluding an agitator mechanism, comprising:

a filter device comprising a receptacle including a back wall and afront'wall having a screeneddischarge opening formedtherein,

merged,v a sump formed in the bottom of the receptacle, means defining adelivery manifold on said .receptacle'com-- municating with the interiorof the receptacle,

and means for directing laundry liquid into the,

manifold,

said manifold having an opening directing a flushing flow of liquidacross the screen, whereby-filtered material flushed from the screenwill settle in the sump.

References Cited by thezExamin'er,

UNITED STATES PATENTS 2,481,979 9/1949 Colley 68-18 2,509,753 5/1950Woodsonv 6823 2,972,876 2/19611 Geldhof 6818 2,984,359 5/1961 OBrien6818 X- 3,040,552 6/1962 Platt et' 'al.1 6818 WILLIAM I. PRICE, PrimaryExaminer.

1. A METHOD OF FILTERING LIQUID CONTAINING FOREIGN MATTER LIABLE TO CLOGA FILTRATION SCREEN, DELIVERING LIQUID CONTAINING THE FOREIGN MATTERINTO A RECEPTACLE HAVING AN OPENING THROUGH AN UPRIGHT WALL AND ACROSSWHICH OPENING A FILTERING SCREEN EXTENDS, AND WHILE CONTINUING TODELIVER RECIRCULATION LIQUID INTO THE RECEPTACLE DIRECTING A FLUSHINGSTREAM OF LIQUID GENERALLY HORIZONTALLY ACROSS THE INNER FACE OF THESCREEN FROM ONE SIDE OF THE OPENING AND INTO A CHAMBER RECEPTACLE BEYONDTHE OPPOSITE SIDE OF THE OPENING, WHEREBY AS THE FLUSHING STREAMDIMINISHES IN VELOCITY INTO SAID CHAMBER SPACE FOREIGN MATERIAL FLUSHEDFROM THE SCREEN TENDS TO SINK TO THE BOTTOM OF THE RECEPTACLE.